Generalization of the Lamé problem for three-stage decelerated corrosion process of an elastic hollow sphere

The paper presents an analytical solution to Lamé's problem for a hollow sphere with unknown evolving boundaries. The double-sided uniform corrosion of a linearly elastic thick-walled spherical shell under internal and external pressure is considered. It is assumed that the corrosion rates are piecewise linear functions of the maximum principal stress on the related surface, and exponentially decaying with time. The corrosion process is supposed to be divided into three successive stages: constant rate double-sided corrosive wear, a stage of corrosion accelerated on only one of the surfaces of the shell, and a double-sided mechanochemical corrosion. Closed-formed expressions for all the consecutive stages are obtained with their junction points (corresponding to stress corrosion thresholds) being taken into account.